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Heart-Rate Recovery (HRR)

Source: R/ecg-hrr.R
ecgHRR.Rd

Computes post-exercise heart-rate recovery: the fall in heart rate from the exercise peak to fixed offsets into recovery (Cole et al. 1999; Imai et al. 1994), plus the recovery slope. Accepts either a heart-rate (bpm) or an RR (ms) series.

Usage

ecgHRR(
  rr_or_hr,
  time_sec = NULL,
  peak_time = NULL,
  recovery_offsets_sec = c(60, 120),
  input = c("auto", "hr", "rr"),
  abnormal_bpm = 12
)

Arguments

rr_or_hr

A numeric vector of heart rate (bpm) or RR intervals (ms), or a data.frame with a time_sec column and an hr or rr_ms column.

time_sec

Time of each sample in seconds (required for a vector input; taken from the time_sec column of a data.frame otherwise).

peak_time

Time (seconds) of the exercise peak / start of recovery. If NULL (default), auto-detected as the time of maximum heart rate.

recovery_offsets_sec

Offsets (seconds) after the peak at which to measure recovery (default c(60, 120), i.e. HRR1 and HRR2).

input

Interpretation of a vector input: "auto" (default; decided by magnitude – values above 250 are treated as RR in ms), "hr" or "rr".

abnormal_bpm

HRR at 1 minute below which recovery is flagged abnormal (default 12 bpm, per Cole et al. 1999).

Value

A list with:

peak_time, peak_hr

Recovery start time (s) and peak HR (bpm).

hrr

A data.frame with columns offset_sec, hr_at_offset and hrr_bpm (peak HR minus HR at the offset).

hrr1, hrr2

Convenience scalars for the first two offsets.

slope_bpm_per_min

Slope of a linear fit of HR vs time over the recovery window (negative during recovery).

hrr_1min

HRR at exactly 60 s (used for the abnormal flag).

abnormal

TRUE if hrr_1min < abnormal_bpm.

References

Cole, C.R. et al. (1999). Heart-rate recovery immediately after exercise as a predictor of mortality. New England Journal of Medicine, 341(18), 1351-1357. Imai, K. et al. (1994). Vagally mediated heart rate recovery after exercise is accelerated in athletes but blunted in patients with chronic heart failure. Journal of the American College of Cardiology, 24(6), 1529-1535.

See also

ecgRRintervals, ecgHRVtime

Examples

# HR decays linearly from 170 to 120 bpm over 120 s of recovery
t <- seq(0, 120, by = 1)
hr <- 170 - (170 - 120) * t / 120
res <- ecgHRR(hr, time_sec = t, peak_time = 0)
res$hrr
#>   offset_sec hr_at_offset hrr_bpm
#> 1         60          145      25
#> 2        120          120      50
res$abnormal
#> [1] FALSE